improve glsl pre-roll triangles

[m0dB]

draw the glsl preroll and postroll markers with a patterned texture and some minor additional cleanups

fixes #12015 , initially bringing GLSL waveforms in line with the legacy waveforms, but after discussion going for a slightly different look (closer to the legacy waveform look but with a semi-transparent filling)

before:

initial after

final after (with this PR)

[Swiftb0y]

looks good so far, no complaints from me, except that this is just the shader code atm with the code for the pre-roll still missing.

[m0dB]

oops! pushed!

[ronso0]

could your please add before / after images to the description?

[m0dB]

could your please add before / after images to the description?

done!

(i personally like the filled rectangles better btw)

[m0dB]

could your please add before / after images to the description?

done!

(i personally like the filled rectangles better btw)

but maybe the something in between works best :-)

[ronso0]

(i personally like the filled rectangles better btw)

Me too. The translucent fill is a nice compromise 👍

[Swiftb0y]

Thank you. code looks in good shape, mostly minor suggestions. I really like the look of the translucent anti-aliased triangles. Reminds me of the Vital synth.

[m0dB]

@Swiftb0y I have addressed all comments, please mark the conversations as resolved when re-reviewed.

[Swiftb0y]

please mark the conversations as resolved when re-reviewed.

Did so and also reviewed the new code. Thank you.

[m0dB]

done.

[Swiftb0y]

Thank you, small nitpicks.

[Swiftb0y]

Yes, LGTM. Thank you very much. Highly appreciated. The anti-aliasing is a huuge improvement. Any objections @Holzhaus?
CI failures is unrelated, IIUC @daschuer is looking into it.

[JoergAtGithub]

I just tested this PR with vinyl control signal and the spinnies show it without color (just black):

[m0dB]

@JoergAtGithub Aargh, the only thing I forgot to test myself! Thanks, I will fix this now.

[m0dB]

@JoergAtGithub I have fixed the vinyl quality shader. If you confirm it works, this is ready for merge.

[Holzhaus]

Yes, LGTM. Thank you very much. Highly appreciated. The anti-aliasing is a huuge improvement. Any objections @Holzhaus?

Looks nice. My only objection regarding the previous look was that Software/GL/GLSL/Shader waveform rendering should be consistent. Is this the case now.

[m0dB]

With 50% transparency, it is 50% more consistent ;-)

At least it is now clearly deliberate and can't be mistaken for a bug. So IMO it is "consistent" enough and sacrificing a bit of consistency for a nicer look makes sense.

We could try to change the legacy waveforms to match this look, but I don't think that's worth the effort, particularly taking into account that there is already a lot of variation between the different waveform types.

[JoergAtGithub]

The color of the Vinylcontrol signal is now back.

I'm not sure if the following is a regression, or was always the case, but when I drop the needle, I see the signal outside of the round area:

Aufzeichnung.2023-10-20.232434.mp4

Maybe it's just me, but I expected this to be masked as the Cover-Art.

[m0dB]

Maybe it's just me, but I expected this to be masked as the Cover-Art.

That would be as simple as swapping the draw order of the mask and the vinyl quality. But I took this order from the original spinny code, and changing this should not be part of this PR.

Merge?

[JoergAtGithub]

Since it's not a regression, let's merge this as it is!

[Swiftb0y]

Thank for this nice visual improvement @m0dB. Thank you for the thorough testing @JoergAtGithub.